Renal apparent diffusion coefficient in diabetic chronic kidney disease: correlation with renal function and CKD stage

Abstract Background Diabetic kidney disease represents a major health burden among diabetic patients, gradually damaging both the glomeruli and the renal tubules, resulting in a gradual decline in kidney function and structural damage . It represents a major contributing factor of chronic kidney disease and later on end-stage renal disease. Functional MRI using DWI-MRI acts as a useful imaging approach for assessing renal parenchymal dysfunction in diabetic individuals in a non-invasive manner. Aim This study aimed to evaluate the role of renal ADC values in diabetic CKD, their relationship with renal function and disease stage, and determine whether ADC measurements can differentiate early-stage CKD from more advanced disease stages. Methods Eighty diabetic patients with CKD were prospectively enrolled and classified according to KDIGO guidelines into an early-stage CKD group (G1, n = 40) and a moderate-to-advanced CKD group (G2–G5, n = 40). All participants underwent renal DWI-MRI with b values of 0, 50, and 800 s/mm 2 on a 1.5-T MRI system. Renal ADC values were calculated and subsequently correlated with serum creatinine levels, estimated glomerular filtration rate (e-GFR), and CKD stage. The diagnostic performance of ADC was assessed using receiver operating characteristic (ROC) analysis. Results Renal ADC values were significantly lower in patients having moderate-to-advanced CKD than in those with early-stage disease (median = 1.6 × 10 −3 mm 2 /s, IQR = 1.5–1.8 vs. median = 2.1 × 10 −3 mm 2 /s, IQR = 2.0–2.2, p < 0.001). ROC analysis determined an ADC cutoff value of ≤ 1.8 × 10 −3 mm 2 /s, which differentiated the two groups with 85% sensitivity and 100% specificity. ADC values showed a strong positive correlation with e-GFR (r = 0.9, p < 0.001) and a strong negative correlation with serum creatinine (r = − 0.91, p < 0.001). ADC values also decreased progressively with advancing CKD stage, although differences among the advanced stages were not statistically significant. Conclusions ADC values derived from diffusion-weighted images act as a supportive, non-invasive imaging tool to assess renal parenchymal dysfunction in diabetic individuals, correlating effectively with chronic kidney disease severity in this population. Nevertheless, the apparent diffusion coefficient has a limited ability to differentiate between advanced stages of CKD (G3–G5). Its value as a supportive, non-invasive imaging tool is primarily effective for early and moderate stages of diabetic kidney disease (stages G1–G3).